Effect of cholestanol and cholesterol-loaded cyclodextrin on stallion sperm function and capacitation post-cryopreservation.

The research paper evaluates the effects of membrane stabilisers on the cryopreservation of stallion semen, which is notably less efficient than that of other species. Stallion sperm was found to be more susceptible to freezing damage, causing severe oxidative stress, DNA damage, and cell death. The research found that membrane stabilisers such as cholesterol-loaded cyclodextrin can significantly reduce these damages, improving the in-vitro capacitation of the sperm.

Research Objectives and Methodology

• The study set out to establish better methods for the cryopreservation of stallion sperm, particularly by reducing the risk of membrane damage and cell death.
• These objectives were achieved by adding membrane stabilizers – cholesterol-loaded cyclodextrin and cholestanol-loaded cyclodextrin – to the freezing medium.
• Semen samples from three stallions were frozen using these stabilizers, with post-thaw evaluations conducted in two different experiments. These were: sperm quality and functional analysis after thawing, and sperm quality and functional analysis after 4 hours of post-thaw incubation in capacitating conditions.

Assessment Parameters

• Various parameters were considered in these assessments, including plasma membrane integrity, mitochondrial membrane potential, membrane lipid disorder, intracellular Ca, tyrosine phosphorylation, acrosome reaction, DNA damage, sperm motility, and binding to the zona pellucida.

Research Findings

• Among the stabilisers used, cholesterol-loaded cyclodextrin was found to be the most efficient in reducing membrane disruption and post-thaw cell damage.
• It was found that this stabilizer also enabled the sperm to capacitate in-vitro, showing higher plasma membrane integrity, mitochondrial membrane potential, sperm motility, and improved binding to the zona pellucida.
• Moreover, the in-vitro capacitated sperm also showed a better response to in-vitro capacitating conditions. This remarkable performance of cholesterol-loaded cyclodextrin indicates its potential as a significant player in stallion sperm cryopreservation.